Pop singer Melanie Martinez, who rose to fame after appearing on the third season of "The Voice" in 2012, is denying allegations that she assaulted her former friend.

Taking to Twitter Monday, aspiring musician Timothy Heller shared a lengthy statement, detailing her alleged assault, which she later revealed to be Martinez, 22. Heller recounted a night during which she "repeatedly said no" to the singer's sexual advances. She also accuses Martinez of forceful penetration with a sex toy and other acts.

As of this writing, Heller's tweet has nearly 127,000 likes and almost 73,000 retweets.

Martinez has denied Heller's accusations, saying she's "horrified and saddened." She goes on to say she and Heller "shared... a close friendship for a period of time," later adding Heller "never said no to what we chose to do together."